The main objective of this research project is to investigate the role of glial (Muller) cells in the development, maturation and maintenance of retinal neurons. These studies involve experiments on the uptake and release of Na ion, K ion and Ca2 ion by glial cells using both biochemical and electrophysiological techniques. In addition, the localization and distribution of lectin receptors and surface antigens on cells in mature and developing retinas will be studied. In the first year, we examined the ultrastructure of isolated Muller cells by electron microscopy and studied the binding of various lectins to isolated Muller cells. During the coming year (1980-1981), we propose: 1) to characterize the biochemical nature of the lectin receptors on isolated Muller cells as to whether they are glycoproteins, glycolipids, or oligosaccharides; 2) to obtain cell cultures of isolated Muller cells; and 3) to study electrophysiological properties of isolated Muller cells by intracellular recording.